1. Field of the Invention
This invention relates to surgical instruments and, more particularly, to a cold scalpel having a sharp edge for forming an incision, and means for irradiating tissue adjacent the cutting edge with laser radiation to provide rapid hemostasis.
2. Description of the Prior Art
A significant problem associated with surgical incisions is the control of bleeding. The problem is particularly acute for surgical removal of burn wound eschar and in surgery of highly vascularized organs such as the liver.
An important factor in the development of burn wound sepsis is the dead tissue of deeply burned areas which completely lose their resistance to invading bacteria. It has long been recognized that prompt, safe removal of the dead tissue is desirable, and attempts to do this by chemical and surgical means have been made. Only surgical removal has been carried out effectively, but with the attendant drawback of creating large blood losses necessitating extensive transfusions. Therefore, the early surgical excision of deep burns is generally limited to patients with moderate sized burns. Early eschar excision is also desirable to promote more rapid wound cover with autograft or homograft. In summary, earlier grafting should markedly decrease the incidence of bacterial wound sepsis, diminish the hypermetabolic response of the severely-burned patient, result in a shortened hospital admission and allow improved functional and cosmetic results.
Similar problems are associated with surgery on highly vascularized organs. Massive hemorrhage is sometimes a complication from small resections or even biopsies of the liver.
The use of focused laser radiation to incise and coagulate tissue has been widely considered, although such techniques have not been altogether satisfactory. Focused laser radiation forms incisions at a much slower rate than the conventional cold scalpel and, since the radiation must be absorbed by the incised tissue in order to create the incision, thermal necrosis to viable cells in the dermis is inevitable which appears responsible for inhibited epithelialization and contraction.
Another surgical device which attempts to simultaneously incise and coagulate tissue is the diathermy scalpel which utilizes high-frequency electrical current for hemostatic incisions. The principal disadvantages of this device, as with the use of focused laser radiation, is its slow speed and its tendency to cause thermal necrosis of viable cells adjacent the incision. Furthermore, there may be some tendency for the diathermy electrode to adhere to highly-vascularized organs since removal of an electrocoagulating electrode from the cut surface of a liver has, in some cases, reactivated bleeding.
Hemostatic incisions have also been attempted using a plasma scalpel in which a stream of high-temperature gases are directed at the tissue surface in order to form the incision and coagulate tissue adjacent the incision. Plasma scalpels exhibit the same disadvantages associated with focused laser radiation or the diathermy scalpel, namely slow excision rates and thermal necrosis. Furthermore, plasma gas embolization has been reported following surgery with the plasma scalpel.